They have a video , so far as I've read that they've been trying to get out here since 2017 or earlier and will premiere in the 2019 Slamdance Film Festival. Hope it makes it to video, dvd as I believe there will be footage of JoAnn Kelly, Rev Wilkins and Fred McDowell...

And here is the promo for the film...with info

In addition here is what they say is the 1968 festival selections album with Nathan Beauregard, Bukka White, Furry Lewis, Rev Wilkins and Joe Callicott